14-3-3 蛋白

介绍了14－3－3蛋白的基本结构和功能,并简要概述了14－3－3蛋白在信号转导,细胞周期调控以及前体蛋白的折叠与运输过程中的作用机理。     

3-Azido-3-deoxy-α-d-altrose

The synthesis of (±)-epilupinine from trans-1-cyanoquinolizidines (IVa) and (IVb), the intermediates of the (±)-lamprolobine synthesis is described.     

问题解答3

问 :感冒了为什么会发热 ?答 :正常人的体温在大脑皮层和丘脑下部体温中枢的调节下保持相对的恒定 ,这主要是通过神经和体液等因素来调节产热和散热速度来实现的。如果产热和散热失去了动态平衡导致体温超出正常范围 ,则称为发热。人的体温一般维持在 3 7℃左右 (口腔温度范围为3 6.3℃ 3 7.2℃ ,腋下温度为 3 6℃ 3 7℃ ,直肠内温度为 3 6.5℃ 3 7.7℃ ) ,通常不会因外界温度的变化而变化。而一旦体温超过 3 9℃ ,则为高热 ,高热持续时间超过两周 ,则称长期高热 ,会严重影响人体的正常生理活动。最常引起人体发热的因素是致热源。与人体发…     

14-3-3蛋白研究进展

14-3-3蛋白是高度保守的、所有真核生物细胞中都普遍存在的、在大多数生物物种中由一个基因家族编码的一类蛋白调控家族。它几乎参与生命体所有的生理反应过程,人们在各种组织细胞中发现了各种不同的14-3-3蛋白。作为与磷酸丝氨酸／苏氨酸结合的第一信号分子,14-3-3蛋白在细胞的信号转导中起着至关重要的作用,尤其是它直接参与调节蛋白激酶和蛋白磷酸化酶的活性,被称为蛋白质与蛋白质相互作用的”桥梁蛋白”;它可以与转录因子结合形成复合体,调节相关基因的表达。一些研究表明,14-3-3蛋白调控机制的紊乱可以直接导致疾病的发生,在临床上14-3-3蛋白常常可以作为诊断的标志物。     

Synthesis of 3′-N-Substituted 3′-Amino-3′-Deoxythymidine Derivatives

Abstract

A series of 3′-N-substituted 3′-amino-3′-deoxythymidine derivatives with alkyl, alkenyl and alkylaryl substituents was synthesized by two methods. The first method involved the reaction of 1-(2,3-dideoxy-3-0-mesyl-5-0-trityl-β-D-threo-pentofuranosyl)thymine with an appropriate amine. In the second method, 3′-amino-5′-0-trityl-3′-deoxy-thymidine served as a synthetic precursor which was reacted with an appropiate aldehyde or ketone followed by sodium borohydride reduction. An improved synthesis of 3′-amino-3′-deoxythymidine from 3′ -azido-5′-0-trityl-3′-deoxythymidine using sodium borohydride was also described.     

信号蛋白质14—3—3研究进展

14－3－3信号蛋白质家族是一组高度保守,分布十分广泛的多功能真核生物蛋白质,具有7个亚型,与各种信号肽分子包括激酶、磷酸酶、膜转移受体等结构,参与细胞内信号传导包括有丝分裂信号转导、细胞周期调节、细胞凋亡等,并对朊蛋白病有重要诊断价值。     

Methylation of elongation factor 1α in mouse 3T3B and 3T3BSV40 cells

Two-dimensional gel electrophoretic (NEPHGE) analysis of proteins from mouse 3T3B and 3T3B/SV40 cells labelled with [methyl-³H]methionine in the presence of cycloheximide have revealed that the elongation factor 1α (EF-1α) in these cells is methylated and that the extent of methylation is higher in the SV40 transformed cell type. It is suggested that methylation may account for differences in growth properties for the different cell types.     

Arachidonic Acid Binds 14-3-3ζ, Releases 14-3-3ζ from Phosphorylated BAD and Induces Aggregation of 14-3-3ζ

Polyunsaturated fatty acids, like arachidonic acid, can bind proteins and affect their function. The 14-3-3 proteins bind phosphorylated sites on a diverse array of client proteins and, in this way, are involved in many intracellular signaling pathways. In this study, we used a novel approach to discover that 14-3-3ζ is able to directly bind arachidonic acid. Furthermore, arachidonic acid, at physiological concentrations, reduced the binding of 14-3-3ζ to phosphorylated BAD, an interaction that is important in regulating apoptosis. In addition, high concentrations of arachidonic acid caused the polymerization of 14-3-3ζ, an event observed in neurodegenerative disorders. Taken together, these results indicate that arachidonic acid directly interacts with 14-3-3ζ and that this interaction may be important in both normal and pathological cellular events. If so, then factors that mediate the release, metabolism and reacylation of arachidonic acid into membranes represent key points of regulation.     

植物14-3-3蛋白研究进展

14-3-3蛋白是真核生物中许多信号传导级联反应的主要调节分子,易于与具有磷酸化的丝氨酸和苏氨酸残基的靶蛋白互作进而调节碳氮代谢、三羧酸循环、莽草酸合成等多种生理过程中的多种酶活性。该文根据近年来国内外对14-3-3蛋白的研究进展,对植物中14-3-3蛋白的发现、基因鉴定、结构和功能以及14-3-3蛋白与其靶蛋白的互作机制进行综述,并对14-3-3蛋白的研究提出了进一步的展望。     

A New Synthesis of 2′,3′-Didehydro-3′-deoxy-3-Alkylthymidine

Abstract

The preparation of 3-alkyl D4T derivatives has been carried out starting from the corresponding 5′-O-t-butyldimethylsilyl-3′-O-methanesulfonylthymidine 2 by way of deprotection-elimination and succesive alkylation reactions.     

Lnc-RAP3对小鼠3T3-L1前脂肪细胞分化的影响

长链非编码RNA (long non-coding RNA, lncRNA)是一类长度大于200nt、没有长开放阅读框架但往往具有mRNA结构特征的RNA,可以在转录及转录后水平参与基因的表达调控。近年来,有研究证实lncRNA对脂肪生成具有重要作用。Lnc-RAP3位于小鼠(Mus musculus)17号染色体,其表达量在小鼠脂肪细胞分化前后呈现显著差异,但其具体的生物学功能尚不清楚。为探讨lnc-RAP3在小鼠3T3-L1前脂肪细胞成脂分化中的作用,本文首先构建了lnc-RAP3的真核表达载体pcDNA3.1-RAP3,利用脂质体将pcDNA3.1-RAP3和人工合成的lnc-RAP3的siRNAs分别转染3T3-L1前脂肪细胞,并对转染后的细胞进行诱导分化,并通过油红O染色、qRT-PCR检测成脂分化相关基因表达等方法比较过表达和敲降lnc-RAP3对3T3-L1前脂肪细胞成脂分化的影响。结果显示,过表达lnc-RAP3后,细胞内脂滴聚集显著减少(P<0.05),在诱导分化第0 d、2 d和4 d时C/EBPα、Glut4、PPARγ、LPL和FAS的表达水平均呈显著(P<0.05)或极显著(P<0.01)下降;敲降lnc-RAP3后,细胞内脂滴聚集显著增多(P<0.05),同时在诱导分化第0 d、2 d时PPARγ、LPL、C/EBPα、FAS和Glut4的表达水平呈显著(P<0.05)或极显著(P<0.01)升高。本研究结果表明,lnc-RAP3可能通过影响成脂分化相关基因的表达来抑制3T3-L1前脂肪细胞的成脂分化。     

Partial 3q duplication syndrome and assignment of D3S5 to 3q25–3q28

Summary We report a girl with a de novo duplication of the distal part of the long arm of chromosome 3 and review the literature. Our patient had the facial characteristics and many other anomalies of the partial 3q duplication syndrome. As a hitherto undescribed symptom in partial 3q trisomy syndrome, she had microphthalmia. The karyotype of this girl was interpreted as an inverse duplication of the terminal portion of chromosome 3: 46,XX,inv dup (3)(pter-q28::q28–q25::q28-qter). Quantitative hybridisation studies with 3p and 3q probes gave a consistent 32 ratio of the relative intensities of the q bands in relation to the p bands between patient and control. This confirmed the presence of a 3q duplication and delineated the location of D3S5 to 3q25–3q28.     

The TF1-ATPase and ATPase activities of assembled α3β3γ, α3β3γδ, and α3β3γε complexes are stimulated by low and inhibited by high concentrations of rhodamine 6G whereas the dye only inhibits the α3β3, and α3β3δ complexes

The ATPase activity of the F₁-ATPase from the thermophilic bacterium PS3 is stimulated at concentrations of rhodamine 6G up to about 10 µM where 70% stimulation is observed at 36°C. Half maximal stimulation is observed at about 3 µM dye. At rhodamine 6G concentrations greater than 10 µM, ATPase activity declines with 50% inhibition observed at about 75 µM dye. The ATPase activities of the ₃₃ and ₃₃ complexes assembled from isolated subunits of TF₁ expressed inE. coli deleted of theunc operon respond to increasing concentrations of rhodamine 6G nearly identically to the response of TF₁. In contrast, the ATPase activities of the ₃₃ and ₃₃ complexes are only inhibited by rhodamine 6G with 50% inhibition observed, respectively, at 35 and 75 µM dye at 36°C. The ATPase activity of TF₁ is stimulated up to 4-fold by the neutral detergent, LDAO. In the presence of stimulating concentrations of LDAO, the ATPase activity of TF₁ is no longer stimulated by rhodamine 6G, but rather, it is inhibited with 50% inhibition observed at about 30 µM dye at 30°C. One interpretation of these results is that binding of rhodamine 6G to a high-affinity site on TF₁ stimulates ATPase activity and unmasks a low-affinity, inhibitory site for the dye which is also exposed by LDAO.     

3C胰岛素泵

2012年5月19日,美敦力宣布722实时动态胰岛素泵系统在中国上市,这是国内首款3C整合系统的胰岛素泵。所谓3C整合系统,即同时实现实时动态血糖监测（CGM）、胰岛素持续输注（CSII）与糖尿病信息管理（CareLink）。     

DNA从头甲基转移酶3a和3b

ＤＮＡ甲基化是真核生物基因表达调控的一种方式。通过在ＤＮＡ的ＣＧ二核苷酸胞嘧啶的第 5位碳原子上加上甲基 ,即可抑制或关闭基因表达 ,催化这一过程的是ＤＮＡ甲基转移酶 (Ｄｎｍｔ)。直到 2年前在哺乳动物中还只鉴定出一种Ｄｎｍｔ,即从人和鼠细胞中克隆出的Ｄｎｍｔ1。Ｄｎｍｔ1在体内和体外都有维持甲基化酶 (ｍａｉｎｔｅｎａｎｃｅｍｅｔｈｙｌａｓｅ)的活性 ,即按照模板的甲基化模式 ,对新生的ＤＮＡ链进行甲基化 ,将亲代的甲基化模式遗传给子代。虽然在体外 ,Ｄｎｍｔ1也能将未修饰ＤＮＡ从头甲基化(ｄｅｎｏｖｏｍｅｔｈｙｌａ…